[Clinicopathological and ALVAL score analysis of pseudotumor-like tissue around aseptic joint arthroplasty]

Objective: To analyze the clinicopathological features of pseudotumor-like tissue around aseptic joint arthroplasty and aseptic lymphocytic vasculitis-associated lesions (ALVAL) scores. The characters of wear granules were observed. Methods: Total 122 cases were retrieved from the surgical pathology files between May 2015 and August 2018 in the department of pathology in Beijing Jishuitan Hospital, which included the knee joint arthroplasty (10 cases) and hip arthroplasty (112 cases). There were 62 females and 60 males. Patients' age ranged from 29 to 86 years (mean 56 years). The pseudotumor-like tissue around aseptic joint arthroplasty were stained with HE and analyzed by two ALVAL score systems. The characters of wear granules were observed by light microscope and polarized light. Results: The cohort included 62 females and 60 males. Patients' age ranged from 29 to 86 years (mean 56 years). Compbell-ALVAL system includes synovial lining,inflammatory infiltrate and tissue organization. The scores were: low (0-4): 18cases; moderate (5-8): 101 cases; high (9-10): 3 cases. Oxford-ALVAL system only evaluated the inflammatory infiltrate,and the scores were:0 grade:56 cases; 1 grade:51 cases; 2 grade: 12 cases; 3 grade:3 cases. Cases with high score in the Compbell-ALVAL system were concordant with the 3 grade of the Oxford-ALVAL system. Under light microscope,the metal particles were small black granules; the polyethylene fibers were needle-like and easily visible in polarized light. The polymethylmethacrylate showed clear spaces because of particle melting. Conclusions: The Compbell-ALVAL scoring system is based on the histologic analysis of pseudotumor-like tissue around aseptic joint arthroplasty, and the Oxford-ALVAL scoring systems is based on lymphocytic response. The wear particles could be differentiated by the features in the light microscope.